Numerous water soluble skin care actives are known for providing a variety of skin care benefits. Historically, actives that are very water soluble (identified as having an A log P of less than −2.0) do not penetrate well into human skin as human skin has a more hydrophobic nature. Steps typically taken to a chassis to enhance penetration of such water-soluble skin care actives can have other negative effects on the overall composition.
For example, PKEK [SEQ ID NO: 1] has been identified as an active useful in providing skin whitening benefits. PKEK [SEQ ID NO: 1] has an A log P of −6.9. When used in a typical skin care composition—oil-in-water chassis with polymeric thickener—penetration of PKEK [SEQ ID NO: 1] is very low. To improve penetration, a new chassis was developed with high levels of emulsifiers and penetration enhancers that help maximize bioavailability. Using this chassis, an improvement in penetration was demonstrated. However, the resulting chassis was considered poor from a sensory perspective as it was overly greasy and caused irritation issues due to the high level of oil components and penetration enhancers.
Similarly, trehalose and xylitol are two known humectants that have A log Ps respectively of −3.5 and −2.5. To obtain desirable penetration levels when using these skin care actives, it is necessary to add a significant percentage of the skin care active to a composition. This results in compositions having a tacky texture/feel that is not desirable to consumers.
Over the years, efforts have been made to mitigate the negative effects caused by inclusion of these skin care actives to enable users to derive the benefits. However, there remains an opportunity to avoid some of these negative effects by simply increasing the efficiency of penetration of the skin care active present in the composition.